This article is very explicit that installing CWM recovery is only for the GT-i9250 and that the:
process here is not for other variants of Samsung Galaxy Nexus, like: GT-i515, GT-i516, GT-L700, i9250T, etc.
However this post says:
There are no hardware differences, just tweaked software (specifically Radios)
Is there any real risk to installing CWM Recovery on the GT-i9250M?